You should consider buying a personal residence that you will live in for a year or so, then rent it out and buy another personal residence.
As far as qualifying. In the old days (pre-2003) lenders typically required a lease agreement if you want to count the income from the rental property. They typically use 75% of the gross rent as income when computing your ratios.
The nice thing about this is that it forces you to be conservative when buying your next (personal residence) property.
To maximize profits you may have to be a renter for a few months between properties so that timing lease of the old property and buying a new one is not as important as getting the best deal.
